What is the Mfr and model# of the Internet Service Providers modem/ONT the NG router is connected too? Be sure your using a good quality LAN cable between the modem and router. CAT6 is recommended.
What channels are you using? Auto? Try setting manual channel 1, 6 or 11 on 2.4Ghz and 40 to 48 channel on 5Ghz. Any Wifi Neighbors near by? If so, how many?
Try disabling the following and see: Armor, Smart Parental Controls or Circle, Traffic Meter.
There is no beta FW for v1 RAX120's. Beta mentioned is for only v2's with random reboot issues. Doesn't solve any wifi problems.
